1. Field of the Invention
The present invention relates to an apparatus for developing an exposed photoresist film formed on the surface of a substrate such as a semiconductor wafer, a glass substrate for a liquid crystal display, a glass substrate for a photomask or a substrate for an optical disk by supplying a developer thereto.
2. Description of the Background Art
In a manufacturing process for a semiconductor device, for example, a slit scan development system has recently been widely employed as a method of developing a photoresist film formed on the surface of a substrate such as a semiconductor wafer. This development system is employed for horizontally linearly moving a developer discharge nozzle having a slit discharge port equivalent to or longer by about several mm than the diameter of the substrate from a first end to a second end of the substrate stationarily horizontally held by a substrate holding part and discharging a developer onto the substrate from the slit discharge port of the developer discharge nozzle for heaping the developer on the substrate, as disclosed in Japanese Patent Laying-Open Gazette No. 11-221511 (1998), for example. When the developer is heaped on the stationary substrate, line width uniformity of a resist film pattern can be remarkably improved.
When the developer discharge nozzle is moved at a speed of 50 mm/sec., for example, in this slit scan development, a substrate of 300 mm in diameter cause developing time difference of 6 seconds at the maximum. In a developing time of about 60 seconds applied in a conventional manufacturing process, development reaction of photoresist substantially converges and hence no work dimension difference exceeding allowance results from the developing time difference caused in the substrate plane. In manufacturing of a recent semiconductor device, however, a hyperfine working technique has been fully put to use and the work dimension allowance has been strictly managed. Therefore, work dimension difference resulting from developing time difference, causing substantially no problem in general, may come into question as the case may be. When the developing time is reduced for improving the throughput, the work dimension difference resulting from the developing time difference disadvantageously remarkably appears.
In order to eliminate developing time difference in a substrate plane, there has recently been proposed a scan rinsing system of providing a rinse discharge nozzle also with a slit discharge port for supplying a rinse (deionized water) onto a substrate for stopping development reaction and moving the rinse discharge nozzle at the same speed and in the same direction as a developer discharge nozzle after holding a prescribed developing time after the developer discharge nozzle heaps a developer on the substrate for discharging the rinse onto the substrate from the slit discharge port of the rinse discharge nozzle.
When a developer discharge nozzle (not shown) heaps a developer 1 on the overall upper surface of a substrate W horizontally held by a substrate holding part 10 so that a rinse discharge nozzle 12 thereafter horizontally moves from a first end to a second end of the substrate W for discharging a rinse 2 onto the substrate W from a slit discharge port thereof as shown in FIG. 8A, however, the rinse 2 discharged from the rinse discharge nozzle 12 flows also frontward along the direction of movement of the rinse discharge nozzle 12, as shown in FIG. 8B. Further, the part of the rinse 2 flowing frontward beyond the rinse discharge nozzle 12 washes away part of the developer 1 located in front of the rinse discharge nozzle 12. Therefore, it follows that development reaction is stopped in front of the rinse discharge nozzle 12 before movement thereof. Consequently, developing time difference in the plane of the substrate W cannot be effectively eliminated, and work dimension difference resulting from the developing time difference cannot be eliminated either.
The present invention is directed to a substrate processing apparatus supplying a developer to a substrate for performing development and thereafter supplying a rinse for stopping the development.
A developing apparatus according to the present invention comprises a substrate holding element substantially horizontally holding a substrate, a developer supply element having a slitlike first discharge port discharging a developer for relatively moving in a first horizontal direction with respect to the substrate and discharging the developer onto the substrate from the first discharge port thereby obtaining a puddle of developer covering the overall upper surface of the substrate, a rinse supply element having a slitlike second discharge port discharging a rinse for relatively moving in the first horizontal direction with respect to the substrate and discharging the rinse onto the substrate from the second discharge port thereby stopping development with the puddle of developer and an anti-flow element preventing a first stream of the rinse, discharged onto the substrate from the second discharge port, flowing frontward in the first horizontal direction and a second stream formed by the puddle of developer washed away by the rinse frontward in the first horizontal direction.
When the developer supply element heaps the developer on the overall upper surface of the substrate held by the substrate holding element and the rinse supply element thereafter discharges the rinse onto the substrate from the slit discharge port while relatively moving in the same direction as the developer supply element with respect to the substrate, the rinse discharged from the slit discharge port neither flows frontward in the direction of relative movement of the rinse supply element nor washes away the developer heaped on the substrate frontward. Therefore, development reaction is not stopped in front of the rinse supply element before movement thereof, whereby developing time difference in the substrate plane can be eliminated.
Accordingly, an object of the present invention is to eliminate development time difference in a substrate plane for eliminating working dimension difference resulting from the development time difference when performing slit scan development/slit scan rinsing.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.